The present invention is directed to the provision of topical pharmaceutical compositions for treating otic infections, particularly acute otitis externa infections caused by two newly discovered bacterial species, Microbacterium sp. nov. otitidis and Microbacterium sp. nov. alconae. The present inventors have isolated these species, and have determined that these species are pathogens in acute otitis externa infections. The present invention is directed to the provision of topical pharmaceutical compositions and methods for treating otic infections that are partially or wholly attributable to these newly discovered bacterial species, as well as ophthalmic and nasal infections wherein these species are acting as pathogens. The compositions and methods of the present invention are based on the use of quinolone antibiotics to treat such infections, particularly second and third generation quinolones, such as gatifloxacin and moxifloxacin, respectively.
Quinolone antibiotics have been previously utilized to treat ophthalmic and otic infections. For example, a topical ophthalmic composition containing the quinolone ciprofloxacin is marketed by Alcon Laboratories, Inc. under the name CILOXAN(trademark) (Ciprofloxacin 0.3%) Ophthalmic Solution, and a topical otic composition containing a combination of ciprofloxacin and hydrocortisone is marketed by Alcon Laboratories, Inc. under the name CIPRO(trademark) HC. The following quinolones have also been utilized in ophthalmic antibiotic compositions:
The foregoing quinolone antibiotic compositions are generally effective in treating ophthalmic infections, and have distinct advantages over prior ophthalmic antibiotic compositions, particularly those having relatively limited spectrums of antimicrobial activity, such as: neomycin, polymyxin B, gentamicin and tobramycin, which are primarily useful against gram negative pathogens; and bacitracin, gramicidin, and erythromycin, which are primarily active against gram positive pathogens. However, despite the general efficacy of the ophthalmic quinolone therapies currently available, there is a need for improved compositions and methods of treatment based on the use of antibiotics that are more effective than existing antibiotics against key ophthalmic pathogens, and less prone to the development of resistance by those pathogens.
There is an even greater need for effective topical compositions and methods for treating otic and nasal infections, particularly bacterial infections. The use of oral antibiotics to treat otic infections in children has limited efficacy, and creates a serious risk of pathogen resistance to the orally administered antibiotics. Although ciprofloxacin has proven to be an effective agent in treating otic infections, there is a need for a better understanding of the etiology of these infections and a corresponding need for therapies that address the causes of these infections more directly and effectively.
Ophthalmic, otic and nasal infections are frequently accompanied by inflammation of the infected ophthalmic, otic and nasal tissues and perhaps even surrounding tissues. Similarly, ophthalmic, otic and nasal surgical procedures that create a risk of microbial infections frequently also cause inflammation of the affected tissues. Thus, there is also a need for ophthalmic, otic and nasal pharmaceutical compositions that combine the anti-infective activity of one or more antibiotics with the anti-inflammatory activity of one or more steroid or non-steroid agents in a single composition.
The invention is based on the use of a potent new class of antibiotics to treat ophthalmic, otic and nasal infections, as well as the use of these antibiotics prior to surgery to sterilize the surgical field and prophylactically following surgery or other trauma to otic, ophthalmic or nasal tissues to minimize the risk of infection. The compositions of the present invention may also be administered to the affected tissues during otic, ophthalmic or nasal surgical procedures to prevent or alleviate post-surgical infection. As utilized herein, the terms xe2x80x9ctreatxe2x80x9d, xe2x80x9ctreatingxe2x80x9d and derivations thereof are intended to include both treatments of existing infections and treatments to prevent or reduce the risk of infections.
The compositions preferably also contain one or more anti-inflammatory agents to treat inflammation associated with infections of otic, ophthalmic, or nasal tissues. The anti-inflammatory component of the compositions is also useful in treating inflammation associated with physical trauma to otic, ophthalmic, or nasal tissues, including inflammation resulting from surgical procedures. The compositions of the present invention are therefore particularly useful in treating inflammation associated with trauma to otic, ophthalmic, or nasal tissues wherein there is either an infection or a risk of an infection resulting from the trauma.
Examples of ophthalmic conditions that may be treated with the compositions of the present invention include conjunctivitis, keratitis, blepharitis, dacyrocystitis, hordeolum and corneal ulcers. The compositions of the invention may also be used prophylactically in connection with various ophthalmic surgical procedures that create a risk of infection.
Examples of otic conditions that may be treated with the compositions of the present invention include otitis externa and otitis media. With respect to the treatment of otitis media, the compositions of the present invention are primarily useful in cases where the tympanic membrane has ruptured or tympanostomy tubes have been implanted. The compositions may also be used to treat infections associated with otic surgical procedures, such as tympanostomy, or to prevent such infections.
The compositions and methods of the present invention are particularly useful in the treatment of acute infections of the external ear canal, which are commonly referred to as xe2x80x9cacute otitis externaxe2x80x9d or xe2x80x9cAOExe2x80x9d. The present invention is based in part on the isolation of two bacterial species that have not previously been identified as pathogens relative to acute otitis externa infections. These bacterial species, which have been named xe2x80x9cMicrobacterium otitidisxe2x80x9d and xe2x80x9cMicrobacterium alconaexe2x80x9d, are described in greater detail below. The present invention is also based in part on a finding that the quinolone antibiotics utilized in the present invention, particularly third generation quinolones, such as Moxifloxacin, have a very high level of antimicrobial activity against these newly discovered pathogens, and therefore are particularly useful in the treatment of acute otitis externa infections involving these pathogens.
The two bacterial species that have been identified as being associated with acute otitis externa infections have also been discovered to be associated with ophthalmic infections. As indicated above, the antibiotics utilized in the present invention have a high level of antimicrobial activity against these newly discovered ophthalmic pathogens, and as a result, the compositions of the present invention are particularly useful in treating ophthalmic infections involving these species.
The compositions of the present invention are specially formulated for topical application to otic, ophthalmic, and nasal tissues. The compositions are preferably sterile, and have physical properties (e.g., osmolality and pH) that are specially suited for application to otic, ophthalmic, and nasal tissues, including tissues that have been compromised as the result of preexisting disease, trauma, surgery or other physical conditions.